nodejs-helloworld

This is a test nodeJs app.

Build Docker Image

Syntax: docker build -t <image_name>:<tag> -f <Dockerfile_name> <build_context>

docker build -t node:1 -f dockerfile.nodejs .

Flag Details:

Advance docker build cmd;

Run Docker Container

Syntax: docker run -id --name <container_name> -p <host_port>:<container_port> <image_name>:<tag>

Example:

docker run -id --name node -p 3001:3000 node:1

Flag Details:

List Docker Images

Syntax: docker images

Example:

docker images

List Running Containers

Syntax: docker ps

Example:

docker ps

List All Containers (including stopped)

Syntax: docker ps -a

Example:

docker ps -a

Stop a Container

Syntax: docker stop <container_name_or_id>

Example:

docker stop node

Remove a Container

Syntax: docker rm <container_name_or_id>

Example:

docker rm node

Remove an Image

Syntax: docker rmi <image_name>:<tag>

Example:

docker rmi node:1

Docker Login

Generate a PAT (Personal Access Token) from a docker.

Step 1: Log in to Docker Hub

Step 2: Go to Security Settings

Step 3: Create a New Token

Docker Login cmd.

Syntax: echo "<your_password_or_PAT>" | docker login -u <username> --password-stdin

Example:

echo "<your_pat_password_here>" | docker login -u <your_docker_user_name> --password-stdin

Docker Push

Syntax:
docker tag <local_image> <username>/<repository>:<tag>
docker push <username>/<repository>:<tag>

Example:

docker tag node:1 <your_docker_user_name>/<your_repo_name>:1
docker push <your_docker_user_name>/<your_repo_name>:1

Docker Pull

Syntax: docker pull <username>/<repository>:<tag>

Example:

docker pull <your_docker_user_name>/<your_repo_name>:1

Using Volume bind in Container

Syntax: docker run -d --name <container_name> -v <host_path>:<container_path> <image_name>:<tag>

Example:

docker run -d --name node -v ./app/:/usr/src/app node:1

Jenkins

Step 1: Create the host directory and set permissions

mkdir -p /opt/jenkins/jenkins_home chown -R 1000:1000 /opt/jenkins/jenkins_home

Step 2: Run Jenkins container

docker run -d \
  --name jenkins \
  -p 8080:8080 \
  -p 50000:50000 \
  -v /opt/jenkins/jenkins_home:/var/jenkins_home \
  jenkins/jenkins:lts

Explanation:

jenkins dokcer sock

docker run -d \
  --name jenkins \
  -u root \
  -p 8080:8080 -p 50000:50000 \
  -v /opt/jenkins/jenkins_home:/var/jenkins_home \
  -v /var/run/docker.sock:/var/run/docker.sock \
  jenkins/jenkins:lts


docker exec -it jenkins bash
apt-get update && apt-get install -y docker.io

Jenkins with Docker

docker run -d \
  --name jenkins-docker \
  -u root \
  -p 8080:8080 -p 50000:50000 \
  -v /opt/jenkins/jenkins_home:/var/jenkins_home \
  -v /var/run/docker.sock:/var/run/docker.sock \
  jenkins/jenkins:lts-jdk17

cat jenkins-run-docker.sh
#!/bin/bash
echo "Stop and remove the running container, if existing !!!"
docker rm -f jenkins 2>/dev/null || echo "No container named jenkins exists, skipping remove."

sleep 2
echo "Creating a new jenkins container with presistent volume."
docker run -d \
  --name jenkins \
  -u root \
  -p 8080:8080 -p 50000:50000 \
  -v /opt/jenkins/jenkins_home:/var/jenkins_home \
  -v /var/run/docker.sock:/var/run/docker.sock \
  jenkins/jenkins:lts
  
  
# 
chmod +x jenkins-run-docker.sh
./jenkins-run-docker.sh



# output:  
root@SagarMalla-System:/opt/jenkins# ./jenkins-run-docker.sh
Stop and remove the running container, if existing !!!
Creating a new jenkins container with presistent volume.
affaa433f1ef5a4347d620f0a2400ba89b6fe82b88468f13804d35706600e29d
root@SagarMalla-System:/opt/jenkins#

docker exec jenkins cat /var/jenkins_home/secrets/initialAdminPassword

Install docker on jenkins (docker inside the docker)

docker exec -it -u root jenkins apt-get update -y
docker exec -it jenkins apt-get install -y docker.io

# docker exec -it jenkins bash -c "apt-get update -y && apt-get install -y git docker.io"

docker exec -it jenkins git -v && docker -v
# 
root@SagarMalla-System:/opt/jenkins# docker exec -it jenkins git -v && docker -v
git version 2.39.5
Docker version 28.3.3, build 980b856
root@SagarMalla-System:/opt/jenkins#

http://192.168.202.228:8080/

Aspect Docker Kubernetes
Role Containerization (build & run containers) Orchestration (manage containers at scale)
Scope Single host Multi-node cluster
Scaling Manual / Docker Swarm Automatic, built-in HPA
Networking Basic container networking Advanced service discovery & load balancing
Storage Volumes PV & PVC (dynamic storage)
High Availability Limited Built-in self-healing & HA
Updates Manual Rolling updates & rollbacks
Best For Running containers locally or small scale Managing containers in production at scale
Aspect Docker Docker Swarm Kubernetes
Role Containerization Orchestration (by Docker) Orchestration (industry standard)
Scope Single host Multi-host clusters Multi-node clusters
Setup Simple Easy, built-in with Docker Complex, more components
Scaling Manual Basic scaling Advanced autoscaling
Networking Basic Simple overlay networking Advanced networking & Ingress
High Availability Limited Basic failover Strong HA & self-healing
Updates Manual Rolling updates Rolling updates & rollbacks
Best For Running containers locally Small-to-medium clusters Large-scale production

Definition of DevOps: DevOps is a culture and set of practices that combine software development (Dev) and IT operations (Ops) to deliver applications faster, more reliably, and with continuous improvement.

Why DevOps:

Short version: DevOps = faster, reliable software through collaboration and automation.

Created By: Sagar Malla